1.5.0

* Implement alpha premultiplication

* Add benchmark to resize

* Only display "Premultiply alpha" if it's one of the rust resize types.

* Add comment about division by zero

.nvmrc

@@ -1 +1 @@
-10.15.2
+10.15.3

codecs/resize/.gitignore

@@ -0,0 +1,5 @@
+**/*.rs.bk
+target
+Cargo.lock
+bin/
+pkg/README.md

codecs/resize/Cargo.toml

@@ -0,0 +1,37 @@
+[package]
+name = "resize"
+version = "0.1.0"
+authors = ["Surma <surma@surma.link>"]
+
+[lib]
+#crate-type = ["cdylib", "rlib"]
+crate-type = ["cdylib"]
+
+[features]
+default = ["console_error_panic_hook", "wee_alloc"]
+
+[dependencies]
+cfg-if = "0.1.2"
+wasm-bindgen = "0.2.38"
+resize = "0.3.0"
+
+# The `console_error_panic_hook` crate provides better debugging of panics by
+# logging them with `console.error`. This is great for development, but requires
+# all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
+# code size when deploying.
+console_error_panic_hook = { version = "0.1.1", optional = true }
+
+# `wee_alloc` is a tiny allocator for wasm that is only ~1K in code size
+# compared to the default allocator's ~10K. It is slower than the default
+# allocator, however.
+#
+# Unfortunately, `wee_alloc` requires nightly Rust when targeting wasm for now.
+wee_alloc = { version = "0.4.2", optional = true }
+
+[dev-dependencies]
+wasm-bindgen-test = "0.2"
+
+[profile.release]
+# Tell `rustc` to optimize for small code size.
+opt-level = "s"
+lto = true

codecs/resize/Dockerfile

@@ -0,0 +1,18 @@
+FROM ubuntu
+RUN apt-get update && \
+  apt-get install -qqy git build-essential cmake python2.7
+RUN git clone --recursive https://github.com/WebAssembly/wabt /usr/src/wabt
+RUN mkdir -p /usr/src/wabt/build
+WORKDIR /usr/src/wabt/build
+RUN cmake .. -DCMAKE_INSTALL_PREFIX=/opt/wabt && \
+  make && \
+  make install
+
+FROM rust
+RUN rustup install nightly && \
+  rustup target add --toolchain nightly wasm32-unknown-unknown && \
+  cargo install wasm-pack
+
+COPY --from=0 /opt/wabt /opt/wabt
+ENV PATH="/opt/wabt/bin:${PATH}"
+WORKDIR /src

codecs/resize/benchmark.js

@@ -0,0 +1,41 @@
+// THIS IS NOT A NODE SCRIPT
+// This is a d8 script. Please install jsvu[1] and install v8.
+// Then run `npm run --silent benchmark`.
+// [1]: https://github.com/GoogleChromeLabs/jsvu
+
+self = global = this;
+load('./pkg/resize.js');
+
+async function init() {
+  //  Adjustable constants.
+  const inputDimensions = 2000;
+  const outputDimensions = 1500;
+  const algorithm = 3; // Lanczos
+  const iterations = new Array(100);
+
+  // Constants. Don’t change.
+  const imageByteSize = inputDimensions * inputDimensions * 4;
+  const imageBuffer = new Uint8ClampedArray(imageByteSize);
+
+  const module = await WebAssembly.compile(readbuffer("./pkg/resize_bg.wasm"));
+  await wasm_bindgen(module);
+  [false, true].forEach(premulti => {
+    print(`\npremultiplication: ${premulti}`);
+    print(`==============================`);
+    for (let i = 0; i < 100; i++) {
+      const start = Date.now();
+      wasm_bindgen.resize(imageBuffer, inputDimensions, inputDimensions, outputDimensions, outputDimensions, algorithm, premulti);
+      iterations[i] = Date.now() - start;
+    }
+    const average = iterations.reduce((sum, c) => sum + c) / iterations.length;
+    const stddev = Math.sqrt(
+      iterations
+        .map(i => Math.pow(i - average, 2))
+        .reduce((sum, c) => sum + c) / iterations.length
+    );
+    print(`n = ${iterations.length}`);
+    print(`Average: ${average}`);
+    print(`StdDev: ${stddev}`);
+  });
+}
+init().catch(e => console.error(e, e.stack));

codecs/resize/build.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -e
+
+echo "============================================="
+echo "Compiling wasm"
+echo "============================================="
+(
+  rustup run nightly \
+    wasm-pack build --target no-modules
+  wasm-strip pkg/resize_bg.wasm
+)
+echo "============================================="
+echo "Compiling wasm  done"
+echo "============================================="
+
+echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+echo "Did you update your docker image?"
+echo "Run \`docker pull ubuntu\`"
+echo "Run \`docker pull rust\`"
+echo "Run \`docker build -t squoosh-resize .\`"
+echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"

codecs/resize/package-lock.json

@@ -0,0 +1,4 @@
+{
+  "name": "resize",
+  "lockfileVersion": 1
+}

codecs/resize/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "resize",
+  "scripts": {
+    "build:image": "docker build -t squoosh-resize .",
+    "build": "docker run --rm -v $(pwd):/src squoosh-resize ./build.sh",
+    "benchmark": "v8 --no-liftoff --no-wasm-tier-up ./benchmark.js"
+  }
+}

codecs/resize/pkg/resize.d.ts

@@ -0,0 +1,12 @@
+/* tslint:disable */
+/**
+* @param {Uint8Array} arg0 
+* @param {number} arg1 
+* @param {number} arg2 
+* @param {number} arg3 
+* @param {number} arg4 
+* @param {number} arg5 
+* @param {boolean} arg6 
+* @returns {Uint8Array} 
+*/
+export function resize(arg0: Uint8Array, arg1: number, arg2: number, arg3: number, arg4: number, arg5: number, arg6: boolean): Uint8Array;

codecs/resize/pkg/resize.js

@@ -0,0 +1,113 @@
+(function() {
+    var wasm;
+    const __exports = {};
+
+
+    let cachegetUint8Memory = null;
+    function getUint8Memory() {
+        if (cachegetUint8Memory === null || cachegetUint8Memory.buffer !== wasm.memory.buffer) {
+            cachegetUint8Memory = new Uint8Array(wasm.memory.buffer);
+        }
+        return cachegetUint8Memory;
+    }
+
+    let WASM_VECTOR_LEN = 0;
+
+    function passArray8ToWasm(arg) {
+        const ptr = wasm.__wbindgen_malloc(arg.length * 1);
+        getUint8Memory().set(arg, ptr / 1);
+        WASM_VECTOR_LEN = arg.length;
+        return ptr;
+    }
+
+    function getArrayU8FromWasm(ptr, len) {
+        return getUint8Memory().subarray(ptr / 1, ptr / 1 + len);
+    }
+
+    let cachedGlobalArgumentPtr = null;
+    function globalArgumentPtr() {
+        if (cachedGlobalArgumentPtr === null) {
+            cachedGlobalArgumentPtr = wasm.__wbindgen_global_argument_ptr();
+        }
+        return cachedGlobalArgumentPtr;
+    }
+
+    let cachegetUint32Memory = null;
+    function getUint32Memory() {
+        if (cachegetUint32Memory === null || cachegetUint32Memory.buffer !== wasm.memory.buffer) {
+            cachegetUint32Memory = new Uint32Array(wasm.memory.buffer);
+        }
+        return cachegetUint32Memory;
+    }
+    /**
+    * @param {Uint8Array} arg0
+    * @param {number} arg1
+    * @param {number} arg2
+    * @param {number} arg3
+    * @param {number} arg4
+    * @param {number} arg5
+    * @param {boolean} arg6
+    * @returns {Uint8Array}
+    */
+    __exports.resize = function(arg0, arg1, arg2, arg3, arg4, arg5, arg6) {
+        const ptr0 = passArray8ToWasm(arg0);
+        const len0 = WASM_VECTOR_LEN;
+        const retptr = globalArgumentPtr();
+        wasm.resize(retptr, ptr0, len0, arg1, arg2, arg3, arg4, arg5, arg6);
+        const mem = getUint32Memory();
+        const rustptr = mem[retptr / 4];
+        const rustlen = mem[retptr / 4 + 1];
+
+        const realRet = getArrayU8FromWasm(rustptr, rustlen).slice();
+        wasm.__wbindgen_free(rustptr, rustlen * 1);
+        return realRet;
+
+    };
+
+    const heap = new Array(32);
+
+    heap.fill(undefined);
+
+    heap.push(undefined, null, true, false);
+
+    let heap_next = heap.length;
+
+    function dropObject(idx) {
+        if (idx < 36) return;
+        heap[idx] = heap_next;
+        heap_next = idx;
+    }
+
+    __exports.__wbindgen_object_drop_ref = function(i) { dropObject(i); };
+
+    function init(path_or_module) {
+        let instantiation;
+        const imports = { './resize': __exports };
+        if (path_or_module instanceof WebAssembly.Module) {
+            instantiation = WebAssembly.instantiate(path_or_module, imports)
+            .then(instance => {
+            return { instance, module: path_or_module }
+        });
+    } else {
+        const data = fetch(path_or_module);
+        if (typeof WebAssembly.instantiateStreaming === 'function') {
+            instantiation = WebAssembly.instantiateStreaming(data, imports)
+            .catch(e => {
+                console.warn("`WebAssembly.instantiateStreaming` failed. Assuming this is because your server does not serve wasm with `application/wasm` MIME type. Falling back to `WebAssembly.instantiate` which is slower. Original error:\n", e);
+                return data
+                .then(r => r.arrayBuffer())
+                .then(bytes => WebAssembly.instantiate(bytes, imports));
+            });
+        } else {
+            instantiation = data
+            .then(response => response.arrayBuffer())
+            .then(buffer => WebAssembly.instantiate(buffer, imports));
+        }
+    }
+    return instantiation.then(({instance}) => {
+        wasm = init.wasm = instance.exports;
+
+    });
+};
+self.wasm_bindgen = Object.assign(init, __exports);
+})();

codecs/resize/pkg/resize_bg.d.ts

@@ -0,0 +1,6 @@
+/* tslint:disable */
+export const memory: WebAssembly.Memory;
+export function __wbindgen_global_argument_ptr(): number;
+export function __wbindgen_malloc(a: number): number;
+export function __wbindgen_free(a: number, b: number): void;
+export function resize(a: number, b: number, c: number, d: number, e: number, f: number, g: number, h: number, i: number): void;

codecs/resize/src/lib.rs

@@ -0,0 +1,79 @@
+extern crate cfg_if;
+extern crate resize;
+extern crate wasm_bindgen;
+
+mod utils;
+
+use cfg_if::cfg_if;
+use resize::Pixel::RGBA;
+use resize::Type;
+use wasm_bindgen::prelude::*;
+
+cfg_if! {
+    // When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
+    // allocator.
+    if #[cfg(feature = "wee_alloc")] {
+        extern crate wee_alloc;
+        #[global_allocator]
+        static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+    }
+}
+
+#[wasm_bindgen]
+#[no_mangle]
+pub fn resize(
+    mut input_image: Vec<u8>,
+    input_width: usize,
+    input_height: usize,
+    output_width: usize,
+    output_height: usize,
+    typ_idx: usize,
+    premultiply: bool,
+) -> Vec<u8> {
+    let typ = match typ_idx {
+        0 => Type::Triangle,
+        1 => Type::Catrom,
+        2 => Type::Mitchell,
+        3 => Type::Lanczos3,
+        _ => panic!("Nope"),
+    };
+    let num_input_pixels = input_width * input_height;
+    let num_output_pixels = output_width * output_height;
+
+    if premultiply {
+        for i in 0..num_input_pixels {
+            for j in 0..3 {
+                input_image[4 * i + j] = ((input_image[4 * i + j] as f32)
+                    * (input_image[4 * i + 3] as f32)
+                    / 255.0) as u8;
+            }
+        }
+    }
+
+    let mut resizer = resize::new(
+        input_width,
+        input_height,
+        output_width,
+        output_height,
+        RGBA,
+        typ,
+    );
+    let mut output_image = Vec::<u8>::with_capacity(num_output_pixels * 4);
+    output_image.resize(num_output_pixels * 4, 0);
+    resizer.resize(input_image.as_slice(), output_image.as_mut_slice());
+
+    if premultiply {
+        for i in 0..num_output_pixels {
+            for j in 0..3 {
+                // We don’t need to worry about division by zero, as division by zero
+                // is well-defined on floats to return `±Inf`. ±Inf is converted to 0
+                // when casting to integers.
+                output_image[4 * i + j] = ((output_image[4 * i + j] as f32) * 255.0
+                    / (output_image[4 * i + 3] as f32))
+                    as u8;
+            }
+        }
+    }
+
+    return output_image;
+}

codecs/resize/src/utils.rs

@@ -0,0 +1,17 @@
+use cfg_if::cfg_if;
+
+cfg_if! {
+    // When the `console_error_panic_hook` feature is enabled, we can call the
+    // `set_panic_hook` function at least once during initialization, and then
+    // we will get better error messages if our code ever panics.
+    //
+    // For more details see
+    // https://github.com/rustwasm/console_error_panic_hook#readme
+    if #[cfg(feature = "console_error_panic_hook")] {
+        extern crate console_error_panic_hook;
+        pub use self::console_error_panic_hook::set_once as set_panic_hook;
+    } else {
+        #[inline]
+        pub fn set_panic_hook() {}
+    }
+}

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "squoosh",
-  "version": "1.3.4",
+  "version": "1.5.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -124,9 +124,9 @@
       "dev": true
     },
     "@types/node": {
-      "version": "10.12.29",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-10.12.29.tgz",
-      "integrity": "sha512-J/tnbnj8HcsBgCe2apZbdUpQ7hs4d7oZNTYA5bekWdP0sr2NGsOpI/HRdDroEi209tEvTcTtxhD0FfED3DhEcw==",
+      "version": "10.12.30",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-10.12.30.tgz",
+      "integrity": "sha512-nsqTN6zUcm9xtdJiM9OvOJ5EF0kOI8f1Zuug27O/rgtxCRJHGqncSWfCMZUP852dCKPsDsYXGvBhxfRjDBkF5Q==",
       "dev": true
     },
     "@types/pretty-bytes": {
@@ -15233,7 +15233,7 @@
         },
         "get-stream": {
           "version": "3.0.0",
-          "resolved": "https://registry.npmjs.org/get-stream/-/get-stream-3.0.0.tgz",
+          "resolved": "http://registry.npmjs.org/get-stream/-/get-stream-3.0.0.tgz",
           "integrity": "sha1-jpQ9E1jcN1VQVOy+LtsFqhdO3hQ=",
           "dev": true
         },
@@ -15245,7 +15245,7 @@
         },
         "load-json-file": {
           "version": "2.0.0",
-          "resolved": "https://registry.npmjs.org/load-json-file/-/load-json-file-2.0.0.tgz",
+          "resolved": "http://registry.npmjs.org/load-json-file/-/load-json-file-2.0.0.tgz",
           "integrity": "sha1-eUfkIUmvgNaWy/eXvKq8/h/inKg=",
           "dev": true,
           "requires": {
@@ -15295,7 +15295,7 @@
         },
         "pify": {
           "version": "2.3.0",
-          "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
+          "resolved": "http://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
           "integrity": "sha1-7RQaasBDqEnqWISY59yosVMw6Qw=",
           "dev": true
         },

package.json

@@ -1,12 +1,12 @@
 {
   "private": true,
   "name": "squoosh",
-  "version": "1.3.4",
+  "version": "1.5.0",
   "license": "apache-2.0",
   "scripts": {
     "start": "webpack-dev-server --host 0.0.0.0 --hot",
     "build": "webpack -p",
-    "lint": "tslint -c tslint.json  -p tsconfig.json -t verbose 'src/**/*.{ts,tsx,js,jsx}'",
+    "lint": "tslint -c tslint.json  -p tsconfig.json -t verbose",
     "lintfix": "tslint -c tslint.json -p tsconfig.json -t verbose --fix 'src/**/*.{ts,tsx,js,jsx}'",
     "sizereport": "node config/size-report.js"
   },
@@ -16,7 +16,7 @@
     }
   },
   "devDependencies": {
-    "@types/node": "10.12.29",
+    "@types/node": "10.12.30",
     "@types/pretty-bytes": "5.1.0",
     "@types/webassembly-js-api": "0.0.2",
     "@webcomponents/custom-elements": "1.2.1",

src/codecs/imagequant/processor.ts

@@ -1,12 +1,12 @@
 import imagequant, { QuantizerModule } from '../../../codecs/imagequant/imagequant';
 import wasmUrl from '../../../codecs/imagequant/imagequant.wasm';
 import { QuantizeOptions } from './processor-meta';
-import { initWasmModule } from '../util';
+import { initEmscriptenModule } from '../util';
 
 let emscriptenModule: Promise<QuantizerModule>;
 
 export async function process(data: ImageData, opts: QuantizeOptions): Promise<ImageData> {
-  if (!emscriptenModule) emscriptenModule = initWasmModule(imagequant, wasmUrl);
+  if (!emscriptenModule) emscriptenModule = initEmscriptenModule(imagequant, wasmUrl);
 
   const module = await emscriptenModule;
 

src/codecs/mozjpeg/encoder.ts

@@ -1,12 +1,12 @@
 import mozjpeg_enc, { MozJPEGModule } from '../../../codecs/mozjpeg_enc/mozjpeg_enc';
 import wasmUrl from '../../../codecs/mozjpeg_enc/mozjpeg_enc.wasm';
 import { EncodeOptions } from './encoder-meta';
-import { initWasmModule } from '../util';
+import { initEmscriptenModule } from '../util';
 
 let emscriptenModule: Promise<MozJPEGModule>;
 
 export async function encode(data: ImageData, options: EncodeOptions): Promise<ArrayBuffer> {
-  if (!emscriptenModule) emscriptenModule = initWasmModule(mozjpeg_enc, wasmUrl);
+  if (!emscriptenModule) emscriptenModule = initEmscriptenModule(mozjpeg_enc, wasmUrl);
 
   const module = await emscriptenModule;
   const resultView = module.encode(data.data, data.width, data.height, options);

src/codecs/optipng/encoder.ts

@@ -1,12 +1,12 @@
 import optipng, { OptiPngModule } from '../../../codecs/optipng/optipng';
 import wasmUrl from '../../../codecs/optipng/optipng.wasm';
 import { EncodeOptions } from './encoder-meta';
-import { initWasmModule } from '../util';
+import { initEmscriptenModule } from '../util';
 
 let emscriptenModule: Promise<OptiPngModule>;
 
 export async function compress(data: BufferSource, options: EncodeOptions): Promise<ArrayBuffer> {
-  if (!emscriptenModule) emscriptenModule = initWasmModule(optipng, wasmUrl);
+  if (!emscriptenModule) emscriptenModule = initEmscriptenModule(optipng, wasmUrl);
 
   const module = await emscriptenModule;
   const resultView = module.compress(data, options);

src/codecs/processor-worker/index.ts

@@ -28,6 +28,16 @@ async function rotate(
   return rotate(data, opts);
 }
 
+async function resize(
+  data: ImageData, opts: import('../resize/processor-meta').WorkerResizeOptions,
+): Promise<ImageData> {
+  const { resize } = await import(
+    /* webpackChunkName: "process-resize" */
+    '../resize/processor');
+
+  return resize(data, opts);
+}
+
 async function optiPngEncode(
   data: BufferSource, options: import('../optipng/encoder-meta').EncodeOptions,
 ): Promise<ArrayBuffer> {
@@ -53,7 +63,7 @@ async function webpDecode(data: ArrayBuffer): Promise<ImageData> {
   return decode(data);
 }
 
-const exports = { mozjpegEncode, quantize, rotate, optiPngEncode, webpEncode, webpDecode };
+const exports = { mozjpegEncode, quantize, rotate, resize, optiPngEncode, webpEncode, webpDecode };
 export type ProcessorWorkerApi = typeof exports;
 
 expose(exports, self);

src/codecs/processor.ts

@@ -6,8 +6,8 @@ import { EncodeOptions as OptiPNGEncoderOptions } from './optipng/encoder-meta';
 import { EncodeOptions as WebPEncoderOptions } from './webp/encoder-meta';
 import { EncodeOptions as BrowserJPEGOptions } from './browser-jpeg/encoder-meta';
 import { EncodeOptions as BrowserWebpEncodeOptions } from './browser-webp/encoder-meta';
-import { BitmapResizeOptions, VectorResizeOptions } from './resize/processor-meta';
-import { resize, vectorResize } from './resize/processor';
+import { BrowserResizeOptions, VectorResizeOptions } from './resize/processor-meta';
+import { browserResize, vectorResize } from './resize/processor-sync';
 import * as browserBMP from './browser-bmp/encoder';
 import * as browserPNG from './browser-png/encoder';
 import * as browserJPEG from './browser-jpeg/encoder';
@@ -130,6 +130,13 @@ export default class Processor {
     return this._workerApi!.rotate(data, opts);
   }
 
+  @Processor._processingJob({ needsWorker: true })
+  workerResize(
+    data: ImageData, opts: import('./resize/processor-meta').WorkerResizeOptions,
+  ): Promise<ImageData> {
+    return this._workerApi!.resize(data, opts);
+  }
+
   @Processor._processingJob({ needsWorker: true })
   mozjpegEncode(
     data: ImageData, opts: MozJPEGEncoderOptions,
@@ -202,9 +209,9 @@ export default class Processor {
 
   // Synchronous jobs
 
-  resize(data: ImageData, opts: BitmapResizeOptions) {
+  resize(data: ImageData, opts: BrowserResizeOptions) {
     this.abortCurrent();
-    return resize(data, opts);
+    return browserResize(data, opts);
   }
 
   vectorResize(data: HTMLImageElement, opts: VectorResizeOptions) {

src/codecs/resize/options.tsx

@@ -1,8 +1,10 @@
 import { h, Component } from 'preact';
 import linkState from 'linkstate';
 import { bind, linkRef } from '../../lib/initial-util';
-import { inputFieldValueAsNumber, inputFieldValue, preventDefault } from '../../lib/util';
-import { ResizeOptions } from './processor-meta';
+import {
+  inputFieldValueAsNumber, inputFieldValue, preventDefault, inputFieldChecked,
+} from '../../lib/util';
+import { ResizeOptions, isWorkerOptions } from './processor-meta';
 import * as style from '../../components/Options/style.scss';
 import Checkbox from '../../components/checkbox';
 import Expander from '../../components/expander';
@@ -17,11 +19,13 @@ interface Props {
 
 interface State {
   maintainAspect: boolean;
+  premultiply: boolean;
 }
 
 export default class ResizerOptions extends Component<Props, State> {
   state: State = {
     maintainAspect: true,
+    premultiply: true,
   };
 
   form?: HTMLFormElement;
@@ -38,6 +42,7 @@ export default class ResizerOptions extends Component<Props, State> {
       width: inputFieldValueAsNumber(width),
       height: inputFieldValueAsNumber(height),
       method: form.resizeMethod.value,
+      premultiply: inputFieldChecked(form.premultiply, true),
       // Casting, as the formfield only returns the correct values.
       fitMethod: inputFieldValue(form.fitMethod, options.fitMethod) as ResizeOptions['fitMethod'],
     };
@@ -87,6 +92,10 @@ export default class ResizerOptions extends Component<Props, State> {
             onChange={this.onChange}
           >
             {isVector && <option value="vector">Vector</option>}
+            <option value="lanczos3">Lanczos3</option>
+            <option value="mitchell">Mitchell</option>
+            <option value="catrom">Catmull-Rom</option>
+            <option value="triangle">Triangle</option>
             <option value="browser-pixelated">Browser pixelated</option>
             <option value="browser-low">Browser low quality</option>
             <option value="browser-medium">Browser medium quality</option>
@@ -117,6 +126,19 @@ export default class ResizerOptions extends Component<Props, State> {
             onInput={this.onHeightInput}
           />
         </label>
+        <Expander>
+          {isWorkerOptions(options) ?
+            <label class={style.optionInputFirst}>
+              <Checkbox
+                name="premultiply"
+                checked={options.premultiply}
+                onChange={this.onChange}
+              />
+              Premultiply alpha channel
+            </label>
+            : null
+          }
+        </Expander>
         <label class={style.optionInputFirst}>
           <Checkbox
             name="maintainAspect"

src/codecs/resize/processor-meta.ts

@@ -1,26 +1,44 @@
-type BitmapResizeMethods = 'browser-pixelated' | 'browser-low' | 'browser-medium' | 'browser-high';
+type BrowserResizeMethods = 'browser-pixelated' | 'browser-low' | 'browser-medium' | 'browser-high';
+type WorkerResizeMethods = 'triangle' | 'catrom' | 'mitchell' | 'lanczos3';
+const workerResizeMethods: WorkerResizeMethods[] = ['triangle', 'catrom', 'mitchell', 'lanczos3'];
 
-export interface ResizeOptions {
+export type ResizeOptions = BrowserResizeOptions | WorkerResizeOptions | VectorResizeOptions;
+
+export interface ResizeOptionsCommon {
   width: number;
   height: number;
-  method: 'vector' | BitmapResizeMethods;
   fitMethod: 'stretch' | 'contain';
 }
 
-export interface BitmapResizeOptions extends ResizeOptions {
-  method: BitmapResizeMethods;
+export interface BrowserResizeOptions extends ResizeOptionsCommon {
+  method: BrowserResizeMethods;
 }
 
-export interface VectorResizeOptions extends ResizeOptions {
+export interface WorkerResizeOptions extends ResizeOptionsCommon {
+  method: WorkerResizeMethods;
+  premultiply: boolean;
+}
+
+export interface VectorResizeOptions extends ResizeOptionsCommon {
   method: 'vector';
 }
 
+/**
+ * Return whether a set of options are worker resize options.
+ *
+ * @param opts
+ */
+export function isWorkerOptions(opts: ResizeOptions): opts is WorkerResizeOptions {
+  return (workerResizeMethods as string[]).includes(opts.method);
+}
+
 export const defaultOptions: ResizeOptions = {
   // Width and height will always default to the image size.
   // This is set elsewhere.
   width: 1,
   height: 1,
   // This will be set to 'vector' if the input is SVG.
-  method: 'browser-high',
+  method: 'lanczos3',
   fitMethod: 'stretch',
+  premultiply: true,
 };

src/codecs/resize/processor-sync.ts

@@ -0,0 +1,35 @@
+import { nativeResize, NativeResizeMethod, drawableToImageData } from '../../lib/util';
+import { BrowserResizeOptions, VectorResizeOptions } from './processor-meta';
+import { getContainOffsets } from './util';
+
+export function browserResize(data: ImageData, opts: BrowserResizeOptions): ImageData {
+  let sx = 0;
+  let sy = 0;
+  let sw = data.width;
+  let sh = data.height;
+
+  if (opts.fitMethod === 'contain') {
+    ({ sx, sy, sw, sh } = getContainOffsets(sw, sh, opts.width, opts.height));
+  }
+
+  return nativeResize(
+    data, sx, sy, sw, sh, opts.width, opts.height,
+    opts.method.slice('browser-'.length) as NativeResizeMethod,
+  );
+}
+
+export function vectorResize(data: HTMLImageElement, opts: VectorResizeOptions): ImageData {
+  let sx = 0;
+  let sy = 0;
+  let sw = data.width;
+  let sh = data.height;
+
+  if (opts.fitMethod === 'contain') {
+    ({ sx, sy, sw, sh } = getContainOffsets(sw, sh, opts.width, opts.height));
+  }
+
+  return drawableToImageData(data, {
+    sx, sy, sw, sh,
+    width: opts.width, height: opts.height,
+  });
+}

src/codecs/resize/processor.ts

@@ -1,49 +1,52 @@
-import { nativeResize, NativeResizeMethod, drawableToImageData } from '../../lib/util';
-import { BitmapResizeOptions, VectorResizeOptions } from './processor-meta';
+import wasmUrl from '../../../codecs/resize/pkg/resize_bg.wasm';
+import '../../../codecs/resize/pkg/resize';
+import { WorkerResizeOptions } from './processor-meta';
+import { getContainOffsets } from './util';
 
-function getContainOffsets(sw: number, sh: number, dw: number, dh: number) {
-  const currentAspect = sw / sh;
-  const endAspect = dw / dh;
-
-  if (endAspect > currentAspect) {
-    const newSh = sw / endAspect;
-    const newSy = (sh - newSh) / 2;
-    return { sw, sh: newSh, sx: 0, sy: newSy };
-  }
-
-  const newSw = sh * endAspect;
-  const newSx = (sw - newSw) / 2;
-  return { sh, sw: newSw, sx: newSx, sy: 0 };
+interface WasmBindgenExports {
+  resize: typeof import('../../../codecs/resize/pkg/resize').resize;
 }
 
-export function resize(data: ImageData, opts: BitmapResizeOptions): ImageData {
-  let sx = 0;
-  let sy = 0;
-  let sw = data.width;
-  let sh = data.height;
+type WasmBindgen = ((url: string) => Promise<void>) & WasmBindgenExports;
 
-  if (opts.fitMethod === 'contain') {
-    ({ sx, sy, sw, sh } = getContainOffsets(sw, sh, opts.width, opts.height));
+declare var wasm_bindgen: WasmBindgen;
+
+const ready = wasm_bindgen(wasmUrl);
+
+function crop(data: ImageData, sx: number, sy: number, sw: number, sh: number): ImageData {
+  const inputPixels = new Uint32Array(data.data.buffer);
+
+  // Copy within the same buffer for speed and memory efficiency.
+  for (let y = 0; y < sh; y += 1) {
+    const start = ((y + sy) * data.width) + sx;
+    inputPixels.copyWithin(y * sw, start, start + sw);
   }
 
-  return nativeResize(
-    data, sx, sy, sw, sh, opts.width, opts.height,
-    opts.method.slice('browser-'.length) as NativeResizeMethod,
+  return new ImageData(
+    new Uint8ClampedArray(inputPixels.buffer.slice(0, sw * sh * 4)),
+    sw, sh,
   );
 }
 
-export function vectorResize(data: HTMLImageElement, opts: VectorResizeOptions): ImageData {
-  let sx = 0;
-  let sy = 0;
-  let sw = data.width;
-  let sh = data.height;
+/** Resize methods by index */
+const resizeMethods: WorkerResizeOptions['method'][] = [
+  'triangle', 'catrom', 'mitchell', 'lanczos3',
+];
+
+export async function resize(data: ImageData, opts: WorkerResizeOptions): Promise<ImageData> {
+  let input = data;
 
   if (opts.fitMethod === 'contain') {
-    ({ sx, sy, sw, sh } = getContainOffsets(sw, sh, opts.width, opts.height));
+    const { sx, sy, sw, sh } = getContainOffsets(data.width, data.height, opts.width, opts.height);
+    input = crop(input, Math.round(sx), Math.round(sy), Math.round(sw), Math.round(sh));
   }
 
-  return drawableToImageData(data, {
-    sx, sy, sw, sh,
-    width: opts.width, height: opts.height,
-  });
+  await ready;
+
+  const result = wasm_bindgen.resize(
+    new Uint8Array(input.data.buffer), input.width, input.height, opts.width, opts.height,
+    resizeMethods.indexOf(opts.method), opts.premultiply,
+  );
+
+  return new ImageData(new Uint8ClampedArray(result.buffer), opts.width, opts.height);
 }

src/codecs/resize/util.ts

@@ -0,0 +1,14 @@
+export function getContainOffsets(sw: number, sh: number, dw: number, dh: number) {
+  const currentAspect = sw / sh;
+  const endAspect = dw / dh;
+
+  if (endAspect > currentAspect) {
+    const newSh = sw / endAspect;
+    const newSy = (sh - newSh) / 2;
+    return { sw, sh: newSh, sx: 0, sy: newSy };
+  }
+
+  const newSw = sh * endAspect;
+  const newSx = (sw - newSw) / 2;
+  return { sh, sw: newSw, sx: newSx, sy: 0 };
+}

src/codecs/util.ts

@@ -2,7 +2,7 @@ type ModuleFactory<M extends EmscriptenWasm.Module> = (
   opts: EmscriptenWasm.ModuleOpts,
 ) => M;
 
-export function initWasmModule<T extends EmscriptenWasm.Module>(
+export function initEmscriptenModule<T extends EmscriptenWasm.Module>(
   moduleFactory: ModuleFactory<T>,
   wasmUrl: string,
 ): Promise<T> {

src/codecs/webp/decoder.ts

@@ -1,11 +1,11 @@
 import webp_dec, { WebPModule } from '../../../codecs/webp_dec/webp_dec';
 import wasmUrl from '../../../codecs/webp_dec/webp_dec.wasm';
-import { initWasmModule } from '../util';
+import { initEmscriptenModule } from '../util';
 
 let emscriptenModule: Promise<WebPModule>;
 
 export async function decode(data: ArrayBuffer): Promise<ImageData> {
-  if (!emscriptenModule) emscriptenModule = initWasmModule(webp_dec, wasmUrl);
+  if (!emscriptenModule) emscriptenModule = initEmscriptenModule(webp_dec, wasmUrl);
 
   const module = await emscriptenModule;
   const rawImage = module.decode(data);

src/codecs/webp/encoder.ts

@@ -1,12 +1,12 @@
 import webp_enc, { WebPModule } from '../../../codecs/webp_enc/webp_enc';
 import wasmUrl from '../../../codecs/webp_enc/webp_enc.wasm';
 import { EncodeOptions } from './encoder-meta';
-import { initWasmModule } from '../util';
+import { initEmscriptenModule } from '../util';
 
 let emscriptenModule: Promise<WebPModule>;
 
 export async function encode(data: ImageData, options: EncodeOptions): Promise<ArrayBuffer> {
-  if (!emscriptenModule) emscriptenModule = initWasmModule(webp_enc, wasmUrl);
+  if (!emscriptenModule) emscriptenModule = initEmscriptenModule(webp_enc, wasmUrl);
 
   const module = await emscriptenModule;
   const resultView = module.encode(data.data, data.width, data.height, options);

src/components/compress/index.tsx

@@ -18,20 +18,14 @@ import * as browserTIFF from '../../codecs/browser-tiff/encoder-meta';
 import * as browserJP2 from '../../codecs/browser-jp2/encoder-meta';
 import * as browserBMP from '../../codecs/browser-bmp/encoder-meta';
 import * as browserPDF from '../../codecs/browser-pdf/encoder-meta';
-import {
-    EncoderState,
-    EncoderType,
-    EncoderOptions,
-    encoderMap,
-} from '../../codecs/encoders';
-import {
-  PreprocessorState,
-  defaultPreprocessorState,
-} from '../../codecs/preprocessors';
+import { EncoderState, EncoderType, EncoderOptions, encoderMap } from '../../codecs/encoders';
+import { PreprocessorState, defaultPreprocessorState } from '../../codecs/preprocessors';
 import { decodeImage } from '../../codecs/decoders';
 import { cleanMerge, cleanSet } from '../../lib/clean-modify';
 import Processor from '../../codecs/processor';
-import { VectorResizeOptions, BitmapResizeOptions } from '../../codecs/resize/processor-meta';
+import {
+  BrowserResizeOptions, isWorkerOptions as isWorkerResizeOptions,
+} from '../../codecs/resize/processor-meta';
 import './custom-els/MultiPanel';
 import Results from '../results';
 import { ExpandIcon, CopyAcrossIconProps } from '../../lib/icons';
@@ -110,10 +104,12 @@ async function preprocessImage(
     if (preprocessData.resize.method === 'vector' && source.vectorImage) {
       result = processor.vectorResize(
         source.vectorImage,
-        preprocessData.resize as VectorResizeOptions,
+        preprocessData.resize,
       );
+    } else if (isWorkerResizeOptions(preprocessData.resize)) {
+      result = await processor.workerResize(result, preprocessData.resize);
     } else {
-      result = processor.resize(result, preprocessData.resize as BitmapResizeOptions);
+      result = processor.resize(result, preprocessData.resize as BrowserResizeOptions);
     }
   }
   if (preprocessData.quantizer.enabled) {
@@ -441,7 +437,7 @@ export default class Compress extends Component<Props, State> {
         newState = cleanMerge(newState, `sides.${i}.latestSettings.preprocessorState.resize`, {
           width: processed.width,
           height: processed.height,
-          method: vectorImage ? 'vector' : 'browser-high',
+          method: vectorImage ? 'vector' : 'lanczos3',
         });
       }